p44 MAP Kinase (Erk1) is a member of a family of mitogen-activated protein kinases that participate in diverse cellular functions, including the regulation of cell growth and differentiation (1,2). Erk1 regulates meiosis and mitosis by phosphorylating a number of transcription factors such as ELK-1. Activation of Erk1 occurs through phosphorylation of threonine 202 and tyrosine 204 (of human MAP kinase) (3). Erk1 is also known to autophosphorylate on tyrosine (3).